In many chronic illnesses, such as rheumatoid arthritis, tuberculosis, hepatitis and numerous other infections, there is a strong increase in serum amyloid A protein (SAA) found in serum. Frequently, the 28 C-terminal amino acid residues from serum amyloid A (SAA) are cleaved off and the rest of the protein (named AA) localizes in certain organs of an infected patient. Oftentimes, the earliest organs affected are the kidneys and the heart. The presence of AA in organs causes the organs to cease functioning. The illness caused by such AA poisoning is termed amyloidosis and, if not treated, is fatal.
Because of the fatal course that amyloidosis can steer, early detection and treatment through increased action against the basic infection is imperative. An extant method for the detection of AA or SAA based on the production of antisera is described in Maury et al, 1984, British Medical Journal, 288:360. The method described therein has not gained widespread acceptance because of the substantial difficulty in producing antisera specific for AA of SAA. Moreover, the method has been the subject of some criticism such as that found in Pepys, 1984, British Medical Journal, 288:859.
The instant invention relates to substantially pure peptides derived from the C-terminal end of amyloid A protein. Moreover, the invention discloses antisera specific for AA generally, and SAA specifically, which antisera constitutes a valuable means for the detection and the determination of the concentration of amyloid A protein in the serum and otherwise.